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Mode and site of action of therapies targeting CGRP signaling

Abstract

Targeting CGRP has proved to be efficacious, tolerable, and safe to treat migraine; however, many patients with migraine do not benefit from drugs that antagonize the CGRPergic system. Therefore, this review focuses on summarizing the general pharmacology of the different types of treatments currently available, which target directly or indirectly the CGRP receptor or its ligand. Moreover, the latest evidence regarding the selectivity and site of action of CGRP small molecule antagonists (gepants) and monoclonal antibodies is critically discussed. Finally, the reasons behind non-responders to anti-CGRP drugs and rationale for combining and/or switching between these therapies are addressed.

Peer Review reports

Role of calcitonin gene-related peptide in nociceptive transmission

Calcitonin gene-related peptide (CGRP) is one of the most investigated molecules in headache pathogenesis. In 1982, a novel 37 amino acid neuropeptide was discovered that is derived from the alternative splicing of calcitonin gene (CALCA) mRNA in neural tissue [1]. It was hence named CGRP, later identified as α-CGRP. This peptide has an amphiphilic α-helix between residues 8–18 that is important in the interaction with CGRP receptors [2], which were found to be of multiple subtypes [3, 4]. CGRP is found in two isoforms in humans: α-CGRP and β-CGRP [5], the latter being encoded by a different CALCB gene, both expressing in the enteric nervous system [6] and the central nervous system (CNS) (reviewed in [7]). However, considering that that only α-CGRP plays a role in sensory trigeminal afferents and trigeminal pain-mediating areas in the CNS, and that for these reasons most studies focus on α-CGRP, this review will be limited to this isoform, with a focus on migraine and the trigeminovascular system.

Although the exact mechanisms underlying the onset of a migraine attack remain to be determined, it is now well-established that the onset of the throbbing headache of migraine is mediated by CGRP release from the trigeminovascular system [8, 9]: a functional pathway consisting of sensory (pseudounipolar) neurons peripherally innervating the cranial meninges and their associated vasculature, whose cell somas are in the trigeminal ganglion (Fig. 1), and centrally projecting axons to the trigeminocervical complex that transmit nociceptive signals to the thalamus and higher order cortical regions [10,11,12]. Immunohistochemical studies have shown that CGRP is highly expressed in sensory unmyelinated C-fibers arising from the trigeminal ganglia and dorsal root ganglia (DRG) as well as their terminals in the spinal cord and brainstem [13, 14], with distribution correlating with CGRP binding site localization [15]. For instance, around 50% of human trigeminal ganglion (TG) neurons show CGRP-immunoreactivity [16]. Similarly, a recent mRNA study found that up to 60% of human DRG neuron express CGRP [17]. Moreover, rodent data has revealed that in comparison to the TG, CGRP mRNA levels are 20x – 250x lower in CNS structures such as lateral medulla and midbrain/hypothalamus, respectively [13]. CGRP released from trigeminal fibers located in the dura mater is unlikely to cross the blood–brain barrier (BBB) due to molecular size [18] and limited diffusion [19, 20].

Fig. 1
figure 1

Anti-CGRP drugs and their peripheral sites of action in the trigeminovascular system. Schematic of CGRP-based therapies highlighting where the CGRP monoclonal antibodies (mAbs), CGRP receptor mAbs, and CGRP receptor antagonists (gepants) have their main site of action. The expression of AMY1 receptors remains to be fully determined. Adapted from [12, 21]

CGRP was additionally shown to be located around isolated dural and cerebral arteries, where it produces vasodilation [22, 23]. Vasodilatory properties of CGRP were found to be one of the most potent identified in humans [24]. In 1987, first attempts to artificially induce headache and develop an experimental human model of migraine began using intravenous nitroglycerin (NTG), another potent vasodilator [25]. NTG administration provoked an initial mild headache in healthy volunteers and a delayed headache with migrainous features in patients with migraine [25], and it was later found that CGRP levels in peripheral vasculature were increased after such induction [26]. Its association with migraine was proved in human studies, where short-term CGRP elevation in local vasculature was observed in patient blood during migraine attacks with and without aura [27]. CGRP levels after migraine attacks were also found to be decreased with sumatriptan treatment and coinciding with headache improvement [28], providing evidence of this neuropeptide being involved in the headache phase of migraine. Further trials led to CGRP being injected into the peripheral vasculature of migraine patients causing a delayed headache with migrainous features, confirming that CGRP plays a key role in migraine pathophysiology [29]. Consequently, novel drugs were developed to target CGRP signaling through either direct blockade of CGRP or its receptor.

Pharmacology

CGRP is a member of the calcitonin (CT)/CGRP family of neuropeptides which also includes CT, amylin, adrenomedullin and intermedin/adrenomedullin 2 [7], with CGRP and amylin being the most closely-related in terms of amino acid sequence and function [30]. The receptors that bind CGRP have only recently been fully characterized [7]. As shown in Fig. 2, the canonical CGRP receptor is atypical among G-protein-coupled receptors, as its functionality depends on the presence of a G-protein coupled calcitonin receptor-like receptor (CLR), a receptor activity-modifying protein 1 (RAMP1), and the receptor component protein (RCP) [31, 32]. The ligand-binding domain of the CGRP receptor is located at the extracellular domain and transmembrane bundle of CLR, with no direct involvement of RAMP1 but acting allosterically to enable CGRP recognition [7, 33]. Moreover, the CLR:RAMP1 complex allows reaching the plasma membrane and binding CGRP with high affinity [34]. Thus, co-expression of CLR and RAMP1 is necessary for CGRP to bind to the canonical CGRP receptor [35].

Fig. 2
figure 2

Crosstalk between CGRP- and Amylin-based therapies. CGRP and amylin 1 (AMY1) receptors are formed by association of either CLR or CTR with RAMP1, respectively. CGRP and amylin are equipotent at the AMY1 receptor, while CGRP is more potent at the canonical CGRP receptor. These receptors have a distinct internalization profile. Current antimigraine drugs targeting CGRP (blue boxes) and potential antimigraine amylin drugs (white boxes) are shown. DACRAs, dual amylin and calcitonin receptor antagonist. Taken and modified from [31, 32]

Moreover, CGRP is equipotent at activating a second receptor, the amylin 1 (AMY1) receptor, which contains RAMP1 but is coupled with the CT receptor (CTR) [31, 36]. The activation of each of these receptors causes an increase in cAMP levels with downstream activation of protein kinase A, suggesting they are of the Gαs-coupled type [7]. Interestingly, in contrast to the CGRP receptor, the AMY1 receptor undergoes scarce internalization (Fig. 2) [31]. As both receptors seem to colocalize in trigeminal fibers [37], there could be relevant feedback loops between CGRP acting at the CGRP and and AMY1 receptors [37, 38]. However, it remains to be determined how this contributes to CGRP physiology and the effectiveness of current anti-CGRP drugs.

It is well-established that CGRP (peptide, receptors, and mRNA) is diffusely expressed across the peripheral and CNS in a variety of cell types [35, 39]. Understanding where CGRP and its receptors are expressed is relevant to understanding the mechanisms of drugs which target this neuropeptide system as well as drug-drug interactions and potential adverse effects.

As shown in Fig. 1, the main sources of CGRP release are from trigeminal afferents [40, 41], that originate in the trigeminal ganglion and which upon electrical, chemical, or mechanical stimulation or during spontaneous migraine attacks release CGRP, leading to dysfunctional nociceptive transmission and eventually headache [27, 28]. Furthermore, recent immunofluorescence studies of these fibers have revealed that CGRP is mainly localized in C-fibers, whereas the components of the CGRP receptor (CLR:RAMP1) are predominantly found in Aδ-fibers [42, 43]. This suggests that local release of CGRP from trigeminal C-fibers activates CGRP receptors in Aδ-fibers and adjacent cells [43, 44].

Centrally, CGRP and its receptor have been shown to be highly expressed in the amygdala, locus coeruleus, striatum, hypothalamus, and parabrachial nucleus [7, 35, 45]. Studies in primates have also shown RAMP1 and CLR mRNA expression in the pineal gland [39]. Interestingly, Purkinje cell bodies in the cerebellum colocalize CGRP and CGRP receptor (CLR and RAMP1) subunits [46], which also suggests that autocrine signaling may occur. As the complexity of the CGRPergic system and the interactions with its family of peptides is yet to be understood, a key question remains highly contested: where is the main antiheadache site of action (peripheral vs central) of anti-CGRP therapies? Thus, the following sections will provide a critical analysis of the current evidence of the likely mode and site of action of CGRP antagonists and antibodies, as well as antimigraine drugs that indirectly modulate CGRP.

Gepants

Due to the key role of CGRP in migraine pathophysiology, selective small-molecule CGRP receptor antagonists (gepants) were synthesized and proved to be effective in the acute [47, 48] and preventive treatment of migraine [49, 50]. Although the first generation of gepants (e.g., olcegepant and telcagepant) was promising, pharmacokinetic and hepatotoxicity limitations stopped their development [51]. However, a new generation of gepants was developed and overall, all have shown efficacy and safety profiles with no demonstrable abnormalities in serum transaminases (reviewed in [52]). As shown in Table 1, ubrogepant, rimegepant and zavegepant (the first intranasal gepant) are effective for the acute treatment of migraine [52,53,54], whereas atogepant and rimegepant have demonstrated to be safe, efficacious and tolerable as a preventive treatment for migraine [49, 50].

Table 1 Gepants currently available

Mode of action

Gepants bind with high affinity to the canonical CGRP receptor (CLR:RAMP1), and they seem to have negligible to low affinity for adrenomedullin receptors, composed of RAMP2 and RAMP3 proteins [36, 55]. However, as shown in Fig. 2, the AMY1 receptor (CTR:RAMP1), one of three amylin receptors, could also be targeted by CGRP receptor antagonists. This is explained by the antagonist selectivity driven by the RAMP receptor subunit and the similar RAMP1 subunit shared by the CGRP and AMY1 receptors [36]. Illustrating this cross-reactivity, the antagonist selectivity of rimegepant is only 30-fold higher at CGRP receptors than AMY1 receptors [56]. The antagonism at these two receptors is a hypothesis proposed to explain the dual inhibition of both C-fibers and Aδ-fibers by atogepant observed in the trigeminal ganglion of rats [57], however the clinical implications of blocking both receptors remain to be determined.

Site of action

Based on their small molecular weight, the gepants could theoretically cross the BBB [51] hence, it would be expected that their antimigraine efficacy is the result of antagonizing the CGRP receptor both peripherally and centrally. In this regard, electrophysiological studies in rats have revealed that the CNS structures being targeted by intravenous or intraperitoneal administration of gepants include second- and third-order nociceptive trigeminovascular neurons [58, 59], as well as the periaqueductal gray and nucleus raphe magnus, descending pain modulatory systems [60, 61]. These drugs were also able to ameliorate cortical spreading depression (CSD)-induced photophobia and hypomobility in mice [62]. However, the placement of recording electrodes or direct delivery of drugs might break the BBB and contribute to the observed effects of gepants. Moreover, positron emission tomography (PET) studies in non-human primates with the CGRP receptor tracer [C-11]MK-4322 and telcagepant indicate that gepants do not require to penetrate the BBB to exert their antimigraine action.

Sur et al. found that after the oral administration of telcagepant only a small percentage could be detected in cerebrospinal fluid (CSF) as compared to plasma (CSF/plasma ratio of ~ 1%) [63]. Furthermore, another study in primate and human brain regions revealed that only supratherapeutic doses of telcagepant were able to achieve a moderate CGRP receptor occupancy (43–58%), while in healthy volunteers clinically-relevant doses only achieved low receptor occupancy (≤ 10%) [64]. Lastly, another study with the same PET tracer found no evidence of CGRP receptor central occupancy after therapeutic doses of telcagepant in migraine patients during ictal and interictal periods [65]. Taken together, these results suggest that at therapeutic concentrations, a central antagonism of the CGRP receptor is probably not required for the efficacy of gepants in migraine treatment. Moreover, gepants have a very limited ability to cross the BBB [66], and it remains to be determined whether they can target CNS areas that are not covered by the BBB (i.e., circumventricular organs), where dense CGRP and amylin binding is present [67, 68], and the clinical relevance, if any.

Anti-CGRP monoclonal antibodies

Compared to gepants, monoclonal antibodies (mAbs) are large heterodimeric protein molecules (molecular weight ~ 150 kDa) designed to block targeted molecules, especially for therapeutic purposes (Table 2). Four monoclonal antibodies have been developed to target CGRP signaling so far. Erenumab acts over the CGRP receptor, whereas fremanezumab, galcanezumab and eptinezumab target the CGRP ligand itself. These four drugs have demonstrated to be safe, efficacious, and tolerable as a preventive treatment for migraine (galcanezumab also for episodic cluster headache prevention) and are currently studied in other headache disorders. Table 3 summarizes their characteristics and current clinical use. As these drugs have been mainly investigated in migraine, this section will focus on the evidence on this primary headache disorder.

Table 2 Molecular characteristics of anti-CGRP monoclonal antibodies and gepants. Adapted from [64, 69,70,71]
Table 3 Anti-CGRP monoclonal antibodies

Mode of action

Erenumab binds to the CLR:RAMP1 extracellular domain interface of the CGRP receptor to block it [72]. However, the binding of erenumab to the CGRP receptor also prevents the action of other two peptides, adrenomedullin and intermedin/adrenomedullin 2, that are also able to act on the CGRP receptor [55]. Erenumab is highly selective for the canonical CGRP receptor (CLR:RAMP1) but can still bind to other receptors with less affinity such as CLR:RAMP2 and CLR:RAMP3 (adrenomedullin receptors), or CTR:RAMP1 (AMY1 receptor) complexes [73]. This is relevant as CGRP is able to activate these other receptors, especially AMY1 [74]. Moreover, genetic variants occurring at the CGRP receptor may influence the peptide and/or drug affinity response [75]. In the case of galcanezumab, fremanezumab and eptinezumab, these monoclonal antibodies bind the same region of CGRP ligand that binds to the receptor, thus rendering both α-CGRP and β-CGRP incapable of binding to the CGRP receptor [76, 77]. Because of this ligand-specific mechanism, there is no evidence that fremanezumab interacts with the AMY1 receptor, therefore not affecting amylin responses [55].

Both CGRP ligand or receptor mechanisms interrupt CGRP-induced signaling via cAMP accumulation and potentially inhibit the CGRP receptor internalization [78]. However, mechanisms of receptor internalization are complex and the drugs themselves can be internalized. Erenumab seems to undergo internalization in CGRP and AMY1 receptor expressing cells, interestingly this was not the case for fremanezumab [55]. Gepants also undergo internalization and due to their different pharmacokinetic profile, they may also block CGRP signaling from within endosomes [79], this could explain the effective use of gepants for acute treatment during concomitant erenumab preventive administration [80]. The meaning and clinical significance of internalization and intracellular signaling as molecular mechanisms remain unknown.

Serum levels of CGRP after treatment have been explored, especially with erenumab, to assess the presence of CGRP up or down-regulation mechanisms induced by the treatment [81,82,83]. Results are still highly controversial and this is mainly due to the different methodologies used, however few studies showed reduction in CGRP levels after treatment [83] or no difference [81, 82], questioning the role of using CGRP as a potential biomarker.

Recently, new molecular mechanisms have been disclosed and it has been demonstrated that CGRP released from trigeminal fibers can signal on surrounding Schwann cells [21] and can be taken up and re-released in the dura. However, the latter mechanism seems not to be mediated by presynaptic CGRP receptors, as CGRP receptor antagonists were not able to block the uptake of CGRP. Such mechanisms may be relevant in regulating CGRP availability and may also influence mAbs and gepants treatment responses [84].

Site of action

The exact site of action of anti-CGRP mAbs in migraine prevention is only partially understood. As previously mentioned, CGRP acts as a vasodilator at the level of the vascular smooth-muscle cells of intracranial arteries as well as a nociceptive neuropeptide in perivascular trigeminal primary afferents [85]. Thus, the probable preventive effect of anti-CGRP mAbs in migraine is mediated by inhibition of first-order trigeminovascular neurons that are involved in pain transmission. Fremanezumab is known to block CGRP-induced vasodilation in human meningeal arteries in vitro [86]. Moreover, preclinical data have shown that, in a migraine rat model of CSD, fremanezumab inhibited Aδ- but not C-type primary afferent meningeal nociceptors, that innervate the cranial dura [44]. Aδ-fibers are activated by release of CGRP from C-type nociceptors after CSD and activate specific type of central trigeminovascular neurons, the high-threshold (HT) neurons, whose input is predominantly from Aδ-fibers and eventually transmit the nociceptive signals to the thalamus [44]. Another study, confirmed that fremanezumab selectively inhibited the activation and sensitization of HT neurons in a rat model of CSD-evoked or mechanical stimulation of the dura [87]. These data remark that the activation of the Aδ-HT nociceptive pathway may be sufficient for the initiation of headache perception and the development of central sensitization and its clinical correlate that is allodynia [44, 87].

Anti-CGRP mAbs are thought to act mainly peripherally, due to their large size. Two studies using radiolabeled mAbs confirmed this hypothesis [20, 69]. In rats with uncompromised BBB, fremanezumab could be detected in the dura, dural blood vessels, trigeminal ganglion, C2 dorsal root ganglion, the parasympathetic sphenopalatine ganglion, and the sympathetic superior cervical ganglion but not in central areas such as the cortex, spinal trigeminal nucleus, thalamus, nor the hypothalamus where the BBB is relatively open [20]. However, all the previous mentioned studies support the concept that by acting in the periphery, the anti-CGRP mAbs also exert a modulation of central neurons, which probably contributes to their preventive effect. This is also observed clinically, where central anticipatory and accompanying symptoms of the headache phase seem to improve with anti-CGRP mAbs treatment [88]. Moreover, translational studies using EEG techniques have shown that abnormal visual cortical activity can be restored with galcanezumab [89] and a study using functional MRI showed that galcanezumab decreases hypothalamic activation [90].

A final remark on the site of action of anti-CGRP mAbs must be done in relation to headache disorders other than migraine. Melo-Carrillo et al. observed that fremanezumab was not able to inhibit the activation of HT neurons from mechanical stimulation of other regions such as the skin or cornea [87], thus suggesting a selectivity of these drugs to migraine, but not to other cranial and/or extracranial pain conditions, such as trigeminal neuralgia. A clinical study has been conducted on erenumab in trigeminal neuralgia with negative results [91]. However, CGRP mechanisms can indeed be present and therefore be targeted by anti-CGRP mAbs in other headache disorders. Galcanezumab is a Food and Drug Administration approved treatment for episodic cluster headache (CH) [92], but the phase 3 randomized controlled trial (RCT) on chronic CH did not meet the primary endpoint [93]. Nevertheless, in clinical practice these latter patients also seem to benefit from the treatment [94]. Eptinezumab and erenumab are currently being studied in episodic and/or chronic CH [95,96,97], whereas studies on fremanezumab in both episodic and chronic CH were terminated following a futility analysis which revealed that primary outcomes were unlikely to be met [98, 99]. Among secondary headache disorders, post-traumatic headache [45, 46] involves CGRP [100, 101], with promising preliminary studies [102], although RCTs on anti-CGRP mAbs are still ongoing [103, 104]. Moreover, the role of CGRP and anti-CGRP mAbs is being investigated in headache attributed to idiopathic intracranial hypertension [105, 106].

Antimigraine drugs that modulate CGRP

5-HT1 agonists

In the last decades, the gold standard for acute migraine treatment has been the triptans, 5-HT1B/1D/(1F) receptor agonists. During a migraine attack, they can normalize the elevated CGRP plasma levels by inhibiting further release from trigeminal afferents, thereby decreasing nociceptive transmission (Fig. 1). Experimentally, triptans inhibit CGRP release from peripheral and central trigeminal fibers, however, low lipophilicity and interactions with BBB efflux transporters limit their central actions in vivo [107]. In addition, activation of a high population of 5-HT1B receptors on vascular smooth muscle is mainly associated with potentially dangerous cardiovascular side effects, contraindicating its use in patients with heart disease and hypertension [108, 109].

Ditans are a new group of acute antimigraine drugs which are highly lipophilic and selective for the 5-HT1F receptor [110]. Lasmiditan is the first drug approved in this class. Mechanistically, ditans inhibit the release of CGRP from peripheral and central trigeminal terminals [111]. Higher incidence of CNS-related adverse effects like dizziness, paresthesia, vertigo, fatigue, and somnolence can be due to the high BBB permeability and abundant expression of 5-HT1F receptor in cortical areas, hippocampal formation, and claustrum as well as throughout the vestibular system [112, 113]. Ditans lack cardiovascular side effects [114], which may offer an alternative to triptans in patients with cardiovascular diseases; however, odds ratio for pain freedom and pain relief at 2 h were lower when compared with most triptans [115].

Preventive drugs

Although the key mechanisms and sites of action for medications used in migraine prevention remain unclear, it seems that almost all affect the trigeminal CGRP system indirectly [116, 117]. They inhibit CGRP release and consequently reverse sensitization in chronic migraine [116, 118]. Therefore, CGRP reduction might be at play in determining the effectiveness of non-specific anti-migraine preventive drugs, whereas interictal CGRP levels can be a predictor of response to these preventives [118, 119].

Topiramate is an antiepileptic drug that can be efficacious in migraine prevention via different mechanisms [116]. Preclinical studies demonstrated that it decreases CGRP release from sensory trigeminal neurons in response to depolarizing stimuli, in a time-concentration manner, hence, decreasing nociception [120]. Topiramate also inhibits nitric oxide/proton mediated CGRP release from peripheral afferents [120]. However, unaltered CGRP plasma levels by a low-dose of topiramate in a small clinical trial indicates that the antimigraine effects of topiramate could be independent from the CGRP pathway [121].

The other non-specific antimigraine medication which acts by inhibiting CGRP release from meningeal and extracranial thin myelinated C-fibers is onabotulinumtoxinA (BoNT-A) [122], an injectable formulation of a neurotoxin derived from the bacterium clostridium botulinum. The first mechanism through which BoNT-A blocks CGRP release is by preventing the adhesion of synaptic vesicles to the cell surface [123]. Furthermore, BoNT-A administration might reduce transient receptor potential (TRP) channel expression, particularly TRP vanilloid 1 (TRPV1) and TRP ankyrin1 (TRPA1), on unmyelinated C-fibers in the synaptic membrane and as a result decrease response to nociceptive stimuli and CGRP release (Fig. 1) [123, 124]. Therefore, BoNT-A can revert and prevent CGRP-dependent activation of thick myelinated Aδ-nociceptors, meningeal vessels, and immune cells [122, 125, 126].

Propranolol is a non-selective β-adrenoceptor antagonist also frequently used to prevent migraine attacks. However, it has been shown that it has agonist effects on prejunctional 5-HT1D and 5-HT1F receptors in trigeminal fibers through which can inhibit the release of CGRP from these fibers that innervate the forehead skin and dura mater [117]. Interestingly, a single point mutation in the seventh transmembrane domain of the 5-HT1 receptor increases 100–1000 fold the affinity of β-adrenoreceptor antagonists for the 5-HT1D/1F receptors [127].

Valproate is widely used as treatment for seizure and bipolar disorder. It also prevents migraine attacks through different mechanisms. Animal studies have shown that it restores brain GABA levels [128], hence neuron activation inhibition [129], that might affect CGRP and c-fos expression via central/peripheral sites of action [130]. Valproate also inhibits NF-kB pathway in the TNC, leading to a reduction in CGRP synthesis [130].

It is remarkable that not only non-CGRP preventive drugs, but also specific medications used for acute migraine attacks can modulate the CGRP pathway. This finding can improve our understanding of migraine pathophysiology and be of clinical interest to determine more efficacious therapeutic strategies.

Non-responders to CGRP-targeted therapies in migraine

The existence of non-responders to anti-CGRP mAbs or gepants is an interesting and complex matter. Several explanations are possible. First, a greater CGRP antagonism at a central level may be necessary for migraine prevention. In this context, future studies comparing directly gepants, that are potentially able to act centrally, and anti-CGRP mAbs may provide insights on this matter. However, at present, clinical trials for each drug report similar responder rates [70, 131] and preclinical data only suggest that, in rat models, anti-CGRP monoclonal antibodies may have, as expected, a longer duration of effect but also a more rapid onset of response [132]. Second, anti-CGRP antagonism may be insufficient due to the existence of concomitant other pathophysiological pathways. CSD, for example, is able to activate C-fiber meningeal nociceptors that eventually activate another type of central trigeminovascular neurons, the wide-dynamic range (WDR) neurons [43, 133]. The absence of CGRP receptors from the meningeal C-fibers renders the C-WDR pathway CGRP-independent, and confirms why in preclinical studies it is unresponsive to fremanezumab [44]. Nevertheless, C-fibers and, consequently, WDR neurons can be inhibited by administration of BoNT-A [134], providing a rationale for associating BoNT-A to anti-CGRP mAbs in clinical practice [124]. Clinical studies are still scarce but have shown potential benefits of combination therapy [125, 135]. Third, non-responders could have a state of central neuron sensitization, supported by the presence of non-ictal allodynia, that is independent from peripheral activation and that cannot be attenuated by anti-CGRP mAbs [136]. In clinical practice, presence of non-ictal allodynia seems to be a useful predictor of lack of response to galcanezumab [136]. Finally, not only molecular mechanisms, as previously mentioned, but also the mode of action may differ from one anti-CGRP mAb to another, influencing treatment response. One fMRI study showed differences between erenumab and galcanezumab in the brain areas with decreased activity after treatment [90]. Although its full meaning is unclear, this finding could still have implications on therapeutic outcomes of anti-CGRP mAbs and potentially further supports switching non-responders to another anti-CGRP mAb (or gepants approved for preventive treatment) as a therapeutic option in clinical practice.

Combining and/or switching drugs that modulate CGRP

It is logical to think that different molecular mechanisms may result in different response rates, tolerability, and side effects. However, at present we lack a real comparative study among anti-CGRP mAbs (or gepants used for preventive treatment) and response rates are at least similar in clinical trials and real-world studies [70, 137,138,139]. Yet, there are indirect clinical signs pointing to different mechanisms. First, side effects are different, and specifically constipation has been described for erenumab, galcanezumab and atogepant [52, 140]. This may be because these drugs can simultaneously block the CGRP and AMY1 receptors that may be more relevant at gastro-intestinal level [141]. Second, in clinical practice there are patients not responding to one anti-CGRP mAb that are still able to respond to another with a different mechanism [142]. The different mechanistic and clinical scenarios are described in Table 4.

Table 4 Mechanistic and clinical scenarios of anti-CGRP mAbs

As some studies are starting to show that combining gepants and triptans [143, 144], or gepants with anti-CGRP mAbs seem safe, well-tolerated and could have synergistic effects on pain relief in patients with migraine [80, 145], a combined antagonism of CGRP may give wider options to clinicians to choose between medications from different classes based on individual patient’s risks and responses Concurrently, the involvement of amylin in migraine pathophysiology is becoming evident [146, 147], which suggests that development of novel drugs targeting the AMY1 receptor, either via selective antagonists or antibodies, might also be effective for treating migraine (Fig. 2). Obviously, further clinical studies are warranted to evaluate the safety and efficacy of dual blockage of CGRP (or CGRP and amylin), due to its diverse physiological functions in the human body.

Other sites of action

As CGRP exerts different physiological functions, CGRP antagonism through anti-CGRP mAbs or gepants may mediate different (side)-effects; it is also worth considering that these drugs might have additional non-sensory antinociceptive sites of action, as resident immune cells, fibroblasts, and dural vessels are capable of modulating the activity of meningeal nociceptors [12, 40]. Clinical studies have demonstrated that these drugs are generally safe and well-tolerated, even at long term [70, 148]. However, concerns on cardiovascular safety have been raised, specifically due to the vasodilating properties of CGRP and its potential protective role during cardiac and/or cerebral ischemia [149]. A preclinical study showed that, although erenumab inhibits the vasodilatory responses of CGRP especially in the distal portion of the human coronary artery, it does not influence those of other vasodilators [150]. A clinical study on erenumab in patients with stable angina showed no significant changes in exercise treadmill test [151], supporting safety in this population. However, further studies assessing cardiovascular safety of anti-CGRP mAbs and gepants should be conducted, specifically focusing on women population that may be more prone to cardiac events involving the distal portion of the coronary artery [152]. Other effects on the vascular system may be responsible for reported cases of Raynaud syndrome in patients treated with mAbs, but data are still unclear and the studies are warranted [153].

Among other sites of action of anti-CGRP mAbs and gepants, data from real-world experience of these drugs have disclosed that the GI can be affected, resulting as previously mentioned, in constipation [52, 141]. These drugs may also block the role of CGRP in hair growth, leading to alopecia [154], and bone formation [155] all these potential effects need to be better investigated.

Conclusion

Drugs that block the trigeminal CGRPergic system are effective in the preventive and acute treatment of migraine. Current lines of evidence indicate that the therapeutic effect of the current anti-CGRP mAbs is mainly peripheral, and this also appears to apply for gepants. Even though gepants could cross the BBB, different studies indicate that this site does not appear to play a prominent role in the antimigraine effects of these drugs. So, all this reveals that migraine attacks can be treated and prevented via peripheral blockage of CGRP. Further research is clearly needed to fully elucidate the pharmacology of anti-CGRP therapies, this could allow us to understand why some patients with migraine are non-responders or stop responding to these medications.

Availability of data and materials

All included references in the present review article are available on the Internet.

References

  1. Amara SG, Jonas V, Rosenfeld MG, Ong ES, Evans RM (1982) Alternative RNA processing in calcitonin gene expression generates mRNAs encoding different polypeptide products. Nature 298:240–244

    CAS  PubMed  Google Scholar 

  2. Howitt SG, Kilk K, Wang Y, Smith DM, Langel U, Poyner DR (2003) The role of the 8–18 helix of CGRP8-37 in mediating high affinity binding to CGRP receptors; coulombic and steric interactions. Br J Pharmacol 138:325–332

    CAS  PubMed  PubMed Central  Google Scholar 

  3. Dennis T, Fournier A, St Pierre S, Quirion R (1989) Structure-activity profile of calcitonin gene-related peptide in peripheral and brain tissues. Evidence for receptor multiplicity. J Pharmacol Exp Ther 251:718–725

    CAS  PubMed  Google Scholar 

  4. Van Rossum D, Hanisch UK, Quirion R (1997) Neuroanatomical localization, pharmacological characterization and functions of CGRP, related peptides and their receptors. Neurosci Biobehav Rev 21:649–678

    PubMed  Google Scholar 

  5. Steenbergh P, Höppener J, Zandberg J, Lips C, Jansz H (1985) A second human calcitonin/CGRP gene. FEBS Lett 183:408–412

    Google Scholar 

  6. Alevizaki M, Shiraishi A, Rassool FV, Ferner GJ, Maclntyre I, Legon S (1986) The calcitonin-like sequence of the β CGRP gene. FEBS Lett 206:47–52

    CAS  PubMed  Google Scholar 

  7. Russo AF, Hay DL (2023) CGRP physiology, pharmacology, and therapeutic targets: migraine and beyond. Physiol Rev 103:1565–1644

    CAS  PubMed  Google Scholar 

  8. Burstein R, Yamamura H, Malick A, Strassman AM (1998) Chemical stimulation of the intracranial dura induces enhanced responses to facial stimulation in brain stem trigeminal neurons. J Neurophysiol 79:964–982

    CAS  PubMed  Google Scholar 

  9. Strassman AM, Levy D (2006) Response properties of dural nociceptors in relation to headache. J Neurophysiol 95:1298–1306

    PubMed  Google Scholar 

  10. Liu-Chen L-Y, Mayberg MR, Moskowitz MA (1983) Immunohistochemical evidence for a substance P-containing trigeminovascular pathway to pial arteries in cats. Brain Res 268:162–166

    CAS  PubMed  Google Scholar 

  11. Goadsby P, Duckworth J (1987) Effect of stimulation of trigeminal ganglion on regional cerebral blood flow in cats. Am J Physiol Regul Integr Comp Physiol 253:R270–R274

    CAS  Google Scholar 

  12. Levy D, Moskowitz MA (2023) Meningeal mechanisms and the migraine connection. Annu Rev Neurosci 46:39–58

    CAS  PubMed  Google Scholar 

  13. Rosenfeld MG, Mermod J-J, Amara SG, Swanson LW, Sawchenko PE, Rivier J et al (1983) Production of a novel neuropeptide encoded by the calcitonin gene via tissue-specific RNA processing. Nature 304:129–135

    CAS  PubMed  Google Scholar 

  14. Iyengar S, Ossipov MH, Johnson KW (2017) The role of calcitonin gene–related peptide in peripheral and central pain mechanisms including migraine. Pain 158:543–559

    CAS  PubMed  PubMed Central  Google Scholar 

  15. Inagaki S, Kito S, Kubota Y, Girgis S, Hillyard CJ, Macintyre I (1986) Autoradiographic localization of calcitonin gene-related peptide binding sites in human and rat brains. Brain Res 374:287–298

    CAS  PubMed  Google Scholar 

  16. Eftekhari S, Salvatore CA, Calamari A, Kane SA, Tajti J, Edvinsson L (2010) Differential distribution of calcitonin gene-related peptide and its receptor components in the human trigeminal ganglion. Neuroscience 169:683–696

    CAS  PubMed  Google Scholar 

  17. Shiers S, Klein RM, Price TJ (2020) Quantitative differences in neuronal subpopulations between mouse and human dorsal root ganglia demonstrated with RNAscope in situ hybridization. Pain 161:2410–2424

    CAS  PubMed  PubMed Central  Google Scholar 

  18. Wiggers A, Ashina H, Hadjikhani N, Sagare A, Zlokovic BV, Lauritzen M et al (2022) Brain barriers and their potential role in migraine pathophysiology. J Headache Pain 23:1–10

    Google Scholar 

  19. Risch M, Vogler B, Dux M, Messlinger K (2021) CGRP outflow into jugular blood and cerebrospinal fluid and permeance for CGRP of rat dura mater. J Headache Pain 22:105

    CAS  PubMed  PubMed Central  Google Scholar 

  20. Noseda R, Schain AJ, Melo-Carrillo A, Tien J, Stratton J, Mai F et al (2020) Fluorescently-labeled fremanezumab is distributed to sensory and autonomic ganglia and the dura but not to the brain of rats with uncompromised blood brain barrier. Cephalalgia 40:229–240

    PubMed  Google Scholar 

  21. De Logu F, Nassini R, Hegron A, Landini L, Jensen DD, Latorre R et al (2022) Schwann cell endosome CGRP signals elicit periorbital mechanical allodynia in mice. Nat Commun 13:646

    PubMed  PubMed Central  Google Scholar 

  22. Edvinsson L, Fredholm BB, Hamel E, Jansen I, Verrecchia C (1985) Perivascular peptides relax cerebral arteries concomitant with stimulation of cyclic adenosine monophosphate accumulation or release of an endothelium-derived relaxing factor in the cat. Neurosci Lett 58:213–217

    CAS  PubMed  Google Scholar 

  23. Hanko J, Hardebo JE, Kåhrström J, Owman C, Sundler F (1985) Calcitonin gene-related peptide is present in mammalian cerebrovascular nerve fibres and dilates pial and peripheral arteries. Neurosci Lett 57:91–95

    CAS  PubMed  Google Scholar 

  24. Brain S, Williams T, Tippins J, Morris H, MacIntyre I (1985) Calcitonin gene-related peptide is a potent vasodilator. Nature 313:54–56

    CAS  PubMed  Google Scholar 

  25. Sicuteri F, Del Bene E, Poggioni M, Bonazzi A (1987) Unmasking latent dysnociception in healthy subjects. Headache 27:180–185

    CAS  PubMed  Google Scholar 

  26. Juhasz G, Zsombok T, Modos EA, Olajos S, Jakab B, Nemeth J et al (2003) NO-induced migraine attack: strong increase in plasma calcitonin gene-related peptide (CGRP) concentration and negative correlation with platelet serotonin release. Pain 106:461–470

    CAS  PubMed  Google Scholar 

  27. Goadsby P, Edvinsson L, Ekman R (1990) Vasoactive peptide release in the extracerebral circulation of humans during migraine headache. Ann Neurol 28:183–187

    CAS  PubMed  Google Scholar 

  28. Goadsby PJ, Edvinsson L (1993) The trigeminovascular system and migraine: studies characterizing cerebrovascular and neuropeptide changes seen in humans and cats. Ann Neurol 33:48–56

    CAS  PubMed  Google Scholar 

  29. Hansen JM, Ashina M (2014) Calcitonin gene-related peptide and migraine with aura: a systematic review. Cephalalgia 34:695–707

    PubMed  Google Scholar 

  30. Hay DL (2017) Amylin. Headache 57:89–96

    PubMed  Google Scholar 

  31. Gingell JJ, Rees TA, Hendrikse ER, Siow A, Rennison D, Scotter J et al (2020) Distinct patterns of internalization of different calcitonin gene-related peptide receptors. ACS Pharmacol Transl Sci 3:296–304

    CAS  PubMed  PubMed Central  Google Scholar 

  32. Labastida-Ramírez A (2021) Pharmacology; where do the mAbs Act, Gepants Versus mAbs. In: Maassen van den Brink A, Martelletti P (eds) Monoclonal antibodies in headache: from bench to patient. Springer International Publishing, Cham, pp 13–23

    Google Scholar 

  33. Liang Y-L, Khoshouei M, Deganutti G, Glukhova A, Koole C, Peat TS et al (2018) Cryo-EM structure of the active, Gs-protein complexed, human CGRP receptor. Nature 561:492–497

    CAS  PubMed  PubMed Central  Google Scholar 

  34. McLatchie LM, Fraser NJ, Main MJ, Wise A, Brown J, Thompson N et al (1998) RAMPs regulate the transport and ligand specificity of the calcitonin-receptor-like receptor. Nature 393:333–339

    CAS  PubMed  Google Scholar 

  35. Warfvinge K, Edvinsson L (2019) Distribution of CGRP and CGRP receptor components in the rat brain. Cephalalgia 39:342–353

    PubMed  Google Scholar 

  36. Garelja ML, Walker CS, Hay DL (2022) CGRP receptor antagonists for migraine. Are they also AMY(1) receptor antagonists? Br J Pharmacol 179:454–459

    CAS  PubMed  Google Scholar 

  37. Rees TA, Russo AF, O’Carroll SJ, Hay DL, Walker CS (2022) CGRP and the calcitonin receptor are co-expressed in mouse, rat and human trigeminal ganglia neurons. Front Physiol 13:860037

    PubMed  PubMed Central  Google Scholar 

  38. Rees TA, Hay DL, Walker CS (2021) Amylin antibodies frequently display cross-reactivity with CGRP: characterization of eight amylin antibodies. Am J Physiol Regul Integr Comp Physiol 320:R697-r703

    CAS  PubMed  Google Scholar 

  39. Eftekhari S, Salvatore CA, Johansson S, Chen TB, Zeng Z, Edvinsson L (2015) Localization of CGRP, CGRP receptor, PACAP and glutamate in trigeminal ganglion. Relation to the blood-brain barrier. Brain Res 1600:93–109

    CAS  PubMed  Google Scholar 

  40. Levy D, Labastida-Ramirez A, MaassenVanDenBrink A (2019) Current understanding of meningeal and cerebral vascular function underlying migraine headache. Cephalalgia 39:1606–1622

    PubMed  Google Scholar 

  41. Messlinger K (2018) The big CGRP flood-sources, sinks and signalling sites in the trigeminovascular system. J Headache Pain 19:1–7

    CAS  Google Scholar 

  42. Edvinsson L, Grell A-S, Warfvinge K (2020) Expression of the CGRP family of neuropeptides and their receptors in the trigeminal ganglion. J Mol Neurosci 70:930–944

    CAS  PubMed  PubMed Central  Google Scholar 

  43. Eftekhari S, Warfvinge K, Blixt FW, Edvinsson L (2013) Differentiation of nerve fibers storing CGRP and CGRP receptors in the peripheral trigeminovascular system. J Pain 14:1289–1303

    CAS  PubMed  Google Scholar 

  44. Melo-Carrillo A, Strassman AM, Nir R-R, Schain AJ, Noseda R, Stratton J et al (2017) Fremanezumab—a humanized monoclonal anti-CGRP antibody—inhibits thinly myelinated (Aδ) but not unmyelinated (C) meningeal nociceptors. J Neurosci 37:10587–10596

    CAS  PubMed  PubMed Central  Google Scholar 

  45. Takahashi K, Mouri T, Sone M, Murakami O, Itoi K, Imai Y et al (1989) Calcitonin gene-related peptide in the human hypothalamus. Endocrinol Jpn 36:409–415

    CAS  PubMed  Google Scholar 

  46. Edvinsson L, Eftekhari S, Salvatore CA, Warfvinge K (2011) Cerebellar distribution of calcitonin gene-related peptide (CGRP) and its receptor components calcitonin receptor-like receptor (CLR) and receptor activity modifying protein 1 (RAMP1) in rat. Mol Cell Neurosci 46:333–339

    CAS  PubMed  Google Scholar 

  47. Olesen J, Diener H-C, Husstedt IW, Goadsby PJ, Hall D, Meier U et al (2004) Calcitonin gene-related peptide receptor antagonist BIBN 4096 BS for the acute treatment of migraine. N Engl J Med 350:1104–1110

    CAS  PubMed  Google Scholar 

  48. Ho TW, Mannix LK, Fan X, Assaid C, Furtek C, Jones CJ et al (2008) Randomized controlled trial of an oral CGRP receptor antagonist, MK-0974, in acute treatment of migraine. Neurology 70:1304–1312

    CAS  PubMed  Google Scholar 

  49. Schwedt TJ, Lipton RB, Ailani J, Silberstein SD, Tassorelli C, Guo H et al (2022) Time course of efficacy of atogepant for the preventive treatment of migraine: results from the randomized, double-blind ADVANCE trial. Cephalalgia 42:3–11

    PubMed  Google Scholar 

  50. Croop R, Lipton RB, Kudrow D, Stock DA, Kamen L, Conway CM et al (2021) Oral rimegepant for preventive treatment of migraine: a phase 2/3, randomised, double-blind, placebo-controlled trial. Lancet 397:51–60

    CAS  PubMed  Google Scholar 

  51. González-Hernández A, Marichal-Cancino BA, García-Boll E, Villalón CM (2020) The locus of action of CGRPergic monoclonal antibodies against migraine: peripheral over central mechanisms. CNS Neurol Disord Drug Targets 19:344–359

    PubMed  Google Scholar 

  52. Messina R, Huessler EM, Puledda F, Haghdoost F, Lebedeva ER, Diener HC (2023) Safety and tolerability of monoclonal antibodies targeting the CGRP pathway and gepants in migraine prevention: a systematic review and network meta-analysis. Cephalalgia 43:3331024231152169

    PubMed  Google Scholar 

  53. Moreno-Ajona D, Pérez-Rodríguez A, Goadsby PJ (2020) Small-molecule CGRP receptor antagonists: a new approach to the acute and preventive treatment of migraine. Med Drug Discov 7:100053

    Google Scholar 

  54. Lipton RB, Croop R, Stock DA, Madonia J, Forshaw M, Lovegren M et al (2023) Safety, tolerability, and efficacy of zavegepant 10 mg nasal spray for the acute treatment of migraine in the USA: a phase 3, double-blind, randomised, placebo-controlled multicentre trial. Lancet Neurol 22:209–217

    CAS  PubMed  Google Scholar 

  55. Bhakta M, Vuong T, Taura T, Wilson DS, Stratton JR, Mackenzie KD (2021) Migraine therapeutics differentially modulate the CGRP pathway. Cephalalgia 41:499–514

    PubMed  PubMed Central  Google Scholar 

  56. Pan KS, Siow A, Hay DL, Walker CS (2020) Antagonism of CGRP signaling by rimegepant at two receptors. Front Pharmacol 11:1240

    CAS  PubMed  PubMed Central  Google Scholar 

  57. Strassman AM, Melo-Carrillo A, Houle TT, Adams A, Brin MF, Burstein R (2022) Atogepant - an orally-administered CGRP antagonist - attenuates activation of meningeal nociceptors by CSD. Cephalalgia 42:933–943

    PubMed  PubMed Central  Google Scholar 

  58. Summ O, Charbit AR, Andreou AP, Goadsby PJ (2010) Modulation of nocioceptive transmission with calcitonin gene-related peptide receptor antagonists in the thalamus. Brain 133:2540–2548

    PubMed  Google Scholar 

  59. Fischer MJ, Koulchitsky S, Messlinger K (2005) The nonpeptide calcitonin gene-related peptide receptor antagonist BIBN4096BS lowers the activity of neurons with meningeal input in the rat spinal trigeminal nucleus. J Neurosci 25:5877–5883

    CAS  PubMed  PubMed Central  Google Scholar 

  60. Huang Y, Brodda-Jansen G, Lundeberg T, Yu LC (2000) Anti-nociceptive effects of calcitonin gene-related peptide in nucleus raphe magnus of rats: an effect attenuated by naloxone. Brain Res 873:54–59

    CAS  PubMed  Google Scholar 

  61. Pozo-Rosich P, Storer RJ, Charbit AR, Goadsby PJ (2015) Periaqueductal gray calcitonin gene-related peptide modulates trigeminovascular neurons. Cephalalgia 35:1298–1307

    CAS  PubMed  Google Scholar 

  62. Tang C, Unekawa M, Kitagawa S, Takizawa T, Kayama Y, Nakahara J et al (2020) Cortical spreading depolarisation-induced facial hyperalgesia, photophobia and hypomotility are ameliorated by sumatriptan and olcegepant. Sci Rep 10:11408

    CAS  PubMed  PubMed Central  Google Scholar 

  63. Sur C, Hargreaves R, Bell I, Dancho M, Graham S, Hostetler E et al (2009) CSF levels and binding pattern of novel CGRP receptor antagonists in rhesus monkey and human central nervous system: toward the development of a PET tracer: PO326. Cephalalgia 29:136–137

    Google Scholar 

  64. Hostetler ED, Joshi AD, Sanabria-Bohorquez S, Fan H, Zeng Z, Purcell M et al (2013) In vivo quantification of calcitonin gene-related peptide receptor occupancy by telcagepant in rhesus monkey and human brain using the positron emission tomography tracer [11C] MK-4232. J Pharmacol Exp Ther 347:478–486

    CAS  PubMed  Google Scholar 

  65. Vermeersch SGG, de Hoon J, De Saint-Hubert B, Derdelinckx I, Serdons K, Bormans G et al (2013) PET imaging in healthy subjects and migraineurs suggests CGRP receptor antagonists do not have to act centrally to achieve clinical efficacy. J Headache Pain 14:P224–P224

    PubMed Central  Google Scholar 

  66. Hargreaves R, Olesen J (2019) Calcitonin gene-related peptide modulators–the history and renaissance of a new migraine drug class. Headache 59:951–970

    PubMed  Google Scholar 

  67. Ueda T, Ugawa S, Saishin Y, Shimada S (2001) Expression of receptor-activity modifying protein (RAMP) mRNAs in the mouse brain. Brain Res Mol Brain Res 93:36–45

    CAS  PubMed  Google Scholar 

  68. Young A (2005) Receptor pharmacology. Adv Pharmacol 52:47–65

    CAS  PubMed  Google Scholar 

  69. Johnson KW, Morin SM, Wroblewski VJ, Johnson MP (2019) Peripheral and central nervous system distribution of the CGRP neutralizing antibody [(125)I] galcanezumab in male rats. Cephalalgia 39:1241–1248

    PubMed  Google Scholar 

  70. Caronna E, Starling AJ (2021) Update on calcitonin gene-related peptide antagonism in the treatment of migraine. Neurol Clin 39:1–19

    PubMed  Google Scholar 

  71. Moreno-Ajona D, Villar-Martínez MD, Goadsby PJ (2022) New generation gepants: migraine acute and preventive medications. J Clin Med 11:1656

    CAS  PubMed  PubMed Central  Google Scholar 

  72. Garces F, Mohr C, Zhang L, Huang C-S, Chen Q, King C et al (2020) Molecular insight into recognition of the CGRPR complex by migraine prevention therapy Aimovig (Erenumab). Cell Rep 30:1714–1723 e1716

    CAS  PubMed  Google Scholar 

  73. Shi L, Lehto SG, Zhu DX, Sun H, Zhang J, Smith BP et al (2016) Pharmacologic characterization of AMG 334, a potent and selective human monoclonal antibody against the calcitonin gene-related peptide receptor. J Pharmacol Exp Ther 356:223–231

    CAS  PubMed  Google Scholar 

  74. Walker CS, Eftekhari S, Bower RL, Wilderman A, Insel PA, Edvinsson L et al (2015) A second trigeminal CGRP receptor: function and expression of the AMY1 receptor. Ann Clin Transl Neurol 2:595–608

    CAS  PubMed  PubMed Central  Google Scholar 

  75. Scuteri D, Corasaniti MT, Tonin P, Nicotera P, Bagetta G (2021) Role of CGRP pathway polymorphisms in migraine: a systematic review and impact on CGRP mAbs migraine therapy. J Headache Pain 22:1–14

    Google Scholar 

  76. David L, Scalley-Kim M, Olland A, White A, Misura K (2021) The eptinezumab: CGRP complex structure–the role of conformational changes in binding stabilization. Bioengineered 12:11076–11086

    CAS  PubMed  PubMed Central  Google Scholar 

  77. Garelja ML, Hay DL (2022) A narrative review of the calcitonin peptide family and associated receptors as migraine targets: calcitonin gene-related peptide and beyond. Headache 62:1093–1104

    PubMed  PubMed Central  Google Scholar 

  78. Manoukian R, Sun H, Miller S, Shi D, Chan B, Xu C (2019) Effects of monoclonal antagonist antibodies on calcitonin gene-related peptide receptor function and trafficking. J Headache Pain 20:1–12

    CAS  Google Scholar 

  79. Yarwood RE, Imlach WL, Lieu T, Veldhuis NA, Jensen DD, Klein Herenbrink C et al (2017) Endosomal signaling of the receptor for calcitonin gene-related peptide mediates pain transmission. Proc Natl Acad Sci U S A 114:12309–12314

    CAS  PubMed  PubMed Central  Google Scholar 

  80. Mullin K, Kudrow D, Croop R, Lovegren M, Conway CM, Coric V et al (2020) Potential for treatment benefit of small molecule CGRP receptor antagonist plus monoclonal antibody in migraine therapy. Neurology 94:e2121–e2125

    CAS  PubMed  PubMed Central  Google Scholar 

  81. Tringali G, Vollono C, Calabresi P, Navarra P (2020) A proof-of-concept study on CGRP plasma levels of migraineurs during a 6-month treatment with ERENUMAB. J Headache Pain 21:1–2

    Google Scholar 

  82. de Vries LS, Garrelds IM, Danser A, Terwindt GM, MaassenVanDenBrink A (2022) Serum CGRP in migraine patients using erenumab as preventive treatment. J Headache Pain 23:1–7

    Google Scholar 

  83. Gárate G, González-Quintanilla V, González A, Pascual M, Pérez-Pereda S, Madera J et al (2023) Serum alpha and beta-CGRP levels in chronic migraine patients before and after monoclonal antibodies against CGRP or its receptor. Ann Neurol 94:285–294

  84. Gupta S, Amrutkar DV, Mataji A, Salmasi H, Hay-Schmidt A, Sheykhzade M et al (2010) Evidence for CGRP re-uptake in rat dura mater encephali. Br J Pharmacol 161:1885–1898

    CAS  PubMed  PubMed Central  Google Scholar 

  85. Ashina M, Hansen JM, Do TP, Melo-Carrillo A, Burstein R, Moskowitz MA (2019) Migraine and the trigeminovascular system—40 years and counting. Lancet Neurol 18:795–804

    PubMed  PubMed Central  Google Scholar 

  86. Ohlsson L, Kronvall E, Stratton J, Edvinsson L (2018) Fremanezumab blocks CGRP induced dilatation in human cerebral, middle meningeal and abdominal arteries. J Headache Pain 19:1–6

    CAS  Google Scholar 

  87. Melo-Carrillo A, Noseda R, Nir R-R, Schain AJ, Stratton J, Strassman AM et al (2017) Selective inhibition of trigeminovascular neurons by fremanezumab: a humanized monoclonal anti-CGRP antibody. J Neurosci 37:7149–7163

    CAS  PubMed  PubMed Central  Google Scholar 

  88. Iannone LF, De Cesaris F, Ferrari A, Benemei S, Fattori D, Chiarugi A (2022) Effectiveness of anti-CGRP monoclonal antibodies on central symptoms of migraine. Cephalalgia 42:1323–1330

    PubMed  Google Scholar 

  89. de Tommaso M, La Rocca M, Quitadamo SG, Ricci K, Tancredi G, Clemente L et al (2022) Central effects of galcanezumab in migraine: a pilot study on Steady State Visual Evoked Potentials and occipital hemodynamic response in migraine patients. J Headache Pain 23:52

    PubMed  PubMed Central  Google Scholar 

  90. Basedau H, Sturm L-M, Mehnert J, Peng K-P, Schellong M, May A (2022) Migraine monoclonal antibodies against CGRP change brain activity depending on ligand or receptor target–an fMRI study. Elife 11:e77146

    CAS  PubMed  PubMed Central  Google Scholar 

  91. Andersen ASS, Maarbjerg S, Noory N, Heinskou TB, Forman JL, Cruccu G et al (2022) Safety and efficacy of erenumab in patients with trigeminal neuralgia in Denmark: a double-blind, randomised, placebo-controlled, proof-of-concept study. Lancet Neurol 21:994–1003

    Google Scholar 

  92. Goadsby PJ, Dodick DW, Leone M, Bardos JN, Oakes TM, Millen BA et al (2019) Trial of galcanezumab in prevention of episodic cluster headache. N Engl J Med 381:132–141

    CAS  PubMed  Google Scholar 

  93. Dodick DW, Goadsby PJ, Lucas C, Jensen R, Bardos JN, Martinez JM et al (2020) Phase 3 randomized, placebo-controlled study of galcanezumab in patients with chronic cluster headache: results from 3-month double-blind treatment. Cephalalgia 40:935–948

    PubMed  PubMed Central  Google Scholar 

  94. Membrilla JA, Torres-Ferrus M, Alpuente A, Caronna E, Pozo-Rosich P (2022) Efficacy and safety of galcanezumab as a treatment of refractory episodic and chronic cluster headache: case series and narrative review. Headache 62:1395–405

    PubMed  Google Scholar 

  95. US National Library of Medicine. ClinicalTrials.gov (2021) Efficacy of Erenumab in Chronic Cluster Headache (CHERUB01). https://classic.clinicaltrials.gov/ct2/show/NCT04970355

  96. US National Library of Medicine. ClinicalTrials.gov (2021) A 1-year Trial to Inform About Long-term Exposure to Eptinezumab in Participants With Chronic Cluster Headache (cCH) (CHRONICLE). https://classic.clinicaltrials.gov/ct2/show/NCT05064397

  97. US National Library of Medicine. ClinicalTrials.gov (2020) Eptinezumab in Participants With Episodic Cluster Headache (ALLEVIATE). https://classic.clinicaltrials.gov/ct2/show/NCT04688775

  98. US National Library of Medicine. ClinicalTrials.gov (2016) A Study to Evaluate the Efficacy and Safety of TEV-48125 (Fremanezumab) for the Prevention of Episodic Cluster Headache (ECH). https://classic.clinicaltrials.gov/ct2/show/NCT02945046

  99. US National Library of Medicine. ClinicalTrials.gov (2016) A Study Comparing the Efficacy and Safety of Fremanezumab (TEV-48125) for the Prevention of Chronic Cluster Headache (CCH). https://classic.clinicaltrials.gov/ct2/show/NCT02964338

  100. Kopruszinski CM, Turnes JM, Swiokla J, Weinstein TJ, Schwedt TJ, Dodick DW et al (2021) CGRP monoclonal antibody prevents the loss of diffuse noxious inhibitory controls (DNIC) in a mouse model of post-traumatic headache. Cephalalgia 41:749–759

    PubMed  Google Scholar 

  101. Navratilova E, Rau J, Oyarzo J, Tien J, Mackenzie K, Stratton J et al (2019) CGRP-dependent and independent mechanisms of acute and persistent post-traumatic headache following mild traumatic brain injury in mice. Cephalalgia 39:1762–1775

    PubMed  Google Scholar 

  102. Ashina H, Iljazi A, Al-Khazali HM, Eigenbrodt AK, Larsen EL, Andersen AM et al (2020) Efficacy, tolerability, and safety of erenumab for the preventive treatment of persistent post-traumatic headache attributed to mild traumatic brain injury: an open-label study. J Headache Pain 21:62

    CAS  PubMed  PubMed Central  Google Scholar 

  103. US National Library of Medicine. ClinicalTrials.gov (2021) Treatment of Acute PTH With a CGRP Receptor mAb in Military Service Members and Civilians With mTBI. https://classic.clinicaltrials.gov/ct2/show/NCT05049057

  104. US National Library of Medicine. ClinicalTrials.gov (2017) A Study to Test if Fremanezumab Reduces Headache in Participants With Posttraumatic Headache (PTH). https://classic.clinicaltrials.gov/ct2/show/NCT03347188

  105. Yiangou A, Mitchell JL, Vijay V, Grech O, Bilton E, Lavery GG et al (2020) Calcitonin gene related peptide monoclonal antibody treats headache in patients with active idiopathic intracranial hypertension. J Headache Pain 21:1–8

    Google Scholar 

  106. Yiangou A, Mitchell JL, Fisher C, Edwards J, Vijay V, Alimajstorovic Z et al (2021) Erenumab for headaches in idiopathic intracranial hypertension: a prospective open-label evaluation. Headache 61:157–169

    PubMed  Google Scholar 

  107. Rubio-Beltrán E, Labastida-Ramírez A, Villalón CM, MaassenVanDenBrink A (2018) Is selective 5-HT(1F) receptor agonism an entity apart from that of the triptans in antimigraine therapy? Pharmacol Ther 186:88–97

    PubMed  Google Scholar 

  108. Tepper SJ, Rapoport AM, Sheftell FD (2002) Mechanisms of action of the 5-HT1B/1D receptor agonists. Arch Neurol 59:1084–1088

    PubMed  Google Scholar 

  109. Goadsby P, Charbit A, Andreou A, Akerman S, Holland P (2009) Neurobiology of migraine. Neuroscience 161:327–341

    CAS  PubMed  Google Scholar 

  110. Clemow DB, Johnson KW, Hochstetler HM, Ossipov MH, Hake AM, Blumenfeld AM (2020) Lasmiditan mechanism of action - review of a selective 5-HT(1F) agonist. J Headache Pain 21:71

    CAS  PubMed  PubMed Central  Google Scholar 

  111. Labastida-Ramírez A, Rubio-Beltrán E, Haanes KA, Chan KY, Garrelds IM, Johnson KW et al (2020) Lasmiditan inhibits calcitonin gene-related peptide release in the rodent trigeminovascular system. Pain 161:1092–1099

    PubMed  PubMed Central  Google Scholar 

  112. Usman HO, Balaban CD (2016) Distribution of 5-HT1F receptors in monkey vestibular and trigeminal ganglion cells. Front Neurol 7:173

    PubMed  PubMed Central  Google Scholar 

  113. Ashina M, Roos C, Li LQ, Komori M, Ayer D, Ruff D et al (2023) Long-term treatment with lasmiditan in patients with migraine: results from the open-label extension of the CENTURION randomized trial. Cephalalgia 43:3331024231161745

    PubMed  Google Scholar 

  114. Rubio-Beltrán E, Labastida-Ramírez A, Haanes KA, van den Bogaerdt A, Bogers A, Zanelli E et al (2019) Characterization of binding, functional activity, and contractile responses of the selective 5-HT(1F) receptor agonist lasmiditan. Br J Pharmacol 176:4681–4695

    PubMed  PubMed Central  Google Scholar 

  115. Yang C-P, Liang C-S, Chang C-M, Yang C-C, Shih P-H, Yau Y-C et al (2021) Comparison of new pharmacologic agents with triptans for treatment of migraine: a systematic review and meta-analysis. JAMA Netw Open 4:e2128544–e2128544

    PubMed  PubMed Central  Google Scholar 

  116. Sprenger T, Viana M, Tassorelli C (2018) Current prophylactic medications for migraine and their potential mechanisms of action. Neurotherapeutics 15:313–323

    CAS  PubMed  PubMed Central  Google Scholar 

  117. Rubio-Beltrán E, Schoon RM, van den Berg J, Schuiling-Veninga CC, Koch BC, Villalón CM et al (2022) Trigeminovascular effects of propranolol in men and women, role for sex steroids. Ann Clin Transl Neurol 9:1405–1416

    PubMed  PubMed Central  Google Scholar 

  118. Cernuda-Morollón E, Ramón C, Martínez-Camblor P, Serrano-Pertierra E, Larrosa D, Pascual J (2015) OnabotulinumtoxinA decreases interictal CGRP plasma levels in patients with chronic migraine. Pain 156:820–824

    PubMed  Google Scholar 

  119. Cernuda-Morollón E, Larrosa D, Ramón C, Vega J, Martínez-Camblor P, Pascual J (2013) Interictal increase of CGRP levels in peripheral blood as a biomarker for chronic migraine. Neurology 81:1191–1196

    PubMed  Google Scholar 

  120. Durham PL, Niemann C, Cady R (2006) Repression of stimulated calcitonin gene-related peptide secretion by topiramate. Headache 46:1291–1295

    PubMed  Google Scholar 

  121. Garcia-Estevez DA, Pardo-Parrado M, Silvarrey-Rodriguez S (2017) Frequent episodic migraine and calcitonin gene-related peptide. Influence of treatment with topiramate and zonisamide on levels of the peptide. Rev Neurol 65:153–156

    CAS  PubMed  Google Scholar 

  122. Melo-Carrillo A, Strassman AM, Schain AJ, Noseda R, Ashina S, Adams A et al (2019) Exploring the effects of extracranial injections of botulinum toxin type A on prolonged intracranial meningeal nociceptors responses to cortical spreading depression in female rats. Cephalalgia 39:1358–1365

    PubMed  PubMed Central  Google Scholar 

  123. Durham PL, Cady R, Cady R (2004) Regulation of calcitonin gene-related peptide secretion from trigeminal nerve cells by botulinum toxin type A: Implications for migraine therapy. Headache 44:35–43

    PubMed  Google Scholar 

  124. Pellesi L, Do TP, Ashina H, Ashina M, Burstein R (2020) Dual therapy with anti-CGRP monoclonal antibodies and botulinum toxin for migraine prevention: is there a rationale? Headache 60:1056–1065

    PubMed  Google Scholar 

  125. Argyriou AA, Dermitzakis EV, Xiromerisiou G, Vikelis M (2022) OnabotulinumtoxinA add-on to monoclonal anti-CGRP antibodies in treatment-refractory chronic migraine. Toxins 14:847

    CAS  PubMed  PubMed Central  Google Scholar 

  126. Gfrerer L, Xu W, Austen W Jr, Ashina S, Melo-Carrillo A, Longhi MS et al (2021) OnabotulinumtoxinA alters inflammatory gene expression and immune cells in chronic headache patients. Brain 145:2436–2449

    PubMed Central  Google Scholar 

  127. Adham N, Tamm JA, Salon JA, Vaysse PJ, Weinshank RL, Branchek TA (1994) A single point mutation increases the affinity of serotonin 5-HT1D alpha, 5-HT1D beta, 5-HT1E and 5-HT1F receptors for beta-adrenergic antagonists. Neuropharmacology 33:387–391

    CAS  PubMed  Google Scholar 

  128. Cutrer FM, Limmroth V, Moskowitz MA (1997) Possible mechanisms of valproate in migraine prophylaxis. Cephalalgia 17:93–100

    CAS  PubMed  Google Scholar 

  129. Sonnenberg J, Mitchelmore C, Macgregor-Leon P, Hempstead J, Morgan J, Curran T (1989) Glutamate receptor agonists increase the expression of Fos, Fra, and AP-1 DNA binding activity in the mammalian brain. J Neurosci Res 24:72–80

    CAS  PubMed  Google Scholar 

  130. Li Y, Zhang Q, Qi D, Zhang L, Yi L, Li Q et al (2016) Valproate ameliorates nitroglycerin-induced migraine in trigeminal nucleus caudalis in rats through inhibition of NF-кB. J Headache Pain 17:1–9

    Google Scholar 

  131. Ailani J, Lipton RB, Goadsby PJ, Guo H, Miceli R, Severt L et al (2021) Atogepant for the preventive treatment of migraine. N Engl J Med 385:695–706

    CAS  PubMed  Google Scholar 

  132. Christensen SL, Petersen S, Kristensen DM, Olesen J, Munro G (2019) Targeting CGRP via receptor antagonism and antibody neutralisation in two distinct rodent models of migraine-like pain. Cephalalgia 39:1827–1837

    PubMed  Google Scholar 

  133. Miller S, Liu H, Warfvinge K, Shi L, Dovlatyan M, Xu C et al (2016) Immunohistochemical localization of the calcitonin gene-related peptide binding site in the primate trigeminovascular system using functional antagonist antibodies. Neuroscience 328:165–183

    CAS  PubMed  Google Scholar 

  134. Burstein R, Zhang X, Levy D, Aoki KR, Brin MF (2014) Selective inhibition of meningeal nociceptors by botulinum neurotoxin type A: therapeutic implications for migraine and other pains. Cephalalgia 34:853–869

    PubMed  PubMed Central  Google Scholar 

  135. Scuteri D, Tonin P, Nicotera P, Vulnera M, Altieri GC, Tarsitano A et al (2022) Pooled analysis of real-world evidence supports anti-CGRP mAbs and OnabotulinumtoxinA combined trial in chronic migraine. Toxins 14:529

    CAS  PubMed  PubMed Central  Google Scholar 

  136. Ashina S, Melo-Carrillo A, Szabo E, Borsook D, Burstein R (2023) Pre-treatment non-ictal cephalic allodynia identifies responders to prophylactic treatment of chronic and episodic migraine patients with galcanezumab: a prospective quantitative sensory testing study (NCT04271202). Cephalalgia 43:03331024221147881

    Google Scholar 

  137. Charles A, Pozo-Rosich P (2019) Targeting calcitonin gene-related peptide: a new era in migraine therapy. Lancet 394:1765–1774

    CAS  PubMed  Google Scholar 

  138. Barbanti P, Aurilia C, Egeo G, Fofi L, Cevoli S, Colombo B et al (2021) Erenumab in the prevention of high-frequency episodic and chronic migraine: Erenumab in Real Life in Italy (EARLY), the first Italian multicenter, prospective real-life study. Headache 61:363–372

    PubMed  Google Scholar 

  139. Torres-Ferrús M, Gallardo VJ, Alpuente A, Caronna E, Gine-Cipres E, Pozo-Rosich P (2021) The impact of anti-CGRP monoclonal antibodies in resistant migraine patients: a real-world evidence observational study. J Neurol 268:3789–3798

  140. Kudrow D, Nguyen L, Semler J, Stroud C, Samaan K, Hoban DB et al (2022) A phase IV clinical trial of gastrointestinal motility in adult patients with migraine before and after initiation of a calcitonin gene-related peptide ligand (galcanezumab) or receptor (erenumab) antagonist. Headache 62:1164–1176

    PubMed  PubMed Central  Google Scholar 

  141. Johnson KW, Li X, Huang X, Heinz BA, Yu J, Li B (2022) Characterization of transit rates in the large intestine of mice following treatment with a CGRP antibody, CGRP receptor antibody, and small molecule CGRP receptor antagonists. Headache 62:848–857

    PubMed  PubMed Central  Google Scholar 

  142. Overeem LH, Peikert A, Hofacker MD, Kamm K, Ruscheweyh R, Gendolla A et al (2022) Effect of antibody switch in non-responders to a CGRP receptor antibody treatment in migraine: a multi-center retrospective cohort study. Cephalalgia 42:291–301

    PubMed  Google Scholar 

  143. Hanna M, Ivans A, Stringfellow J, Jensen C, Coric V, Croop R (2020) Oral rimegepant produces no significant effect on blood pressure when administered concomitantly with SC sumatriptan (4007). Neurology 94 (15 Supplement):4007

  144. Croop R, Ivans A, Anderson MS, Stringfellow J, Bertz R, Hanna M et al (2021) A phase 1 randomized study of hemodynamic effects and pharmacokinetic interactions during concomitant use of rimegepant and sumatriptan in healthy adults. Cephalalgia Rep 4:25158163211007920

    Google Scholar 

  145. Berman G, Croop R, Kudrow D, Halverson P, Lovegren M, Thiry AC et al (2020) Safety of Rimegepant, an oral cgrp receptor antagonist, plus CGRP monoclonal antibodies for migraine. Headache 60:1734–1742

    PubMed  PubMed Central  Google Scholar 

  146. Ghanizada H, Al-Karagholi MA, Walker CS, Arngrim N, Rees T, Petersen J et al (2021) Amylin analog pramlintide induces migraine-like attacks in patients. Ann Neurol 89:1157–1171

    CAS  PubMed  PubMed Central  Google Scholar 

  147. Irimia P, Martinez-Valbuena I, Minguez-Olaondo A, Dominguez-Vivero C, Sanchez-Arias JA, Martinez-Vila E et al (2020) Interictal amylin levels in chronic migraine patients: a case-control study. Cephalalgia 41:604–612

    PubMed  Google Scholar 

  148. Ashina M, Kudrow D, Reuter U, Dolezil D, Silberstein S, Tepper SJ et al (2019) Long-term tolerability and nonvascular safety of erenumab, a novel calcitonin gene-related peptide receptor antagonist for prevention of migraine: a pooled analysis of four placebo-controlled trials with long-term extensions. Cephalalgia 39:1798–1808

    PubMed  Google Scholar 

  149. Zhai L, Sakurai T, Kamiyoshi A, Ichikawa-Shindo Y, Kawate H, Tanaka M et al (2018) Endogenous calcitonin gene-related peptide suppresses ischemic brain injuries and progression of cognitive decline. J Hypertens 36:876–891

    CAS  PubMed  Google Scholar 

  150. Rubio-Beltrán E, Labastida-Ramírez A, Haanes KA, van den Bogaerdt A, Bogers AJ, Dirven C et al (2019) Characterisation of vasodilatory responses in the presence of the CGRP receptor antibody erenumab in human isolated arteries. Cephalalgia 39:1735–1744

    PubMed  Google Scholar 

  151. Depre C, Antalik L, Starling A, Koren M, Eisele O, Lenz RA et al (2018) A randomized, double-blind, placebo-controlled study to evaluate the effect of erenumab on exercise time during a treadmill test in patients with stable angina. Headache 58:715–723

    PubMed  PubMed Central  Google Scholar 

  152. Humphries KH, Pu A, Gao M, Carere RG, Pilote L (2008) Angina with “normal” coronary arteries: sex differences in outcomes. Am Heart J 155:375–381

    PubMed  Google Scholar 

  153. Gérard AO, Merino D, Van Obberghen EK, Rocher F, Destere A, Lantéri-Minet M et al (2022) Calcitonin gene-related peptide-targeting drugs and Raynaud’s phenomenon: a real-world potential safety signal from the WHO pharmacovigilance database. J Headache Pain 23:53

    PubMed  PubMed Central  Google Scholar 

  154. Ruiz M, Cocores A, Tosti A, Goadsby PJ, Monteith TS (2023) Alopecia as an emerging adverse event to CGRP monoclonal antibodies: cases Series, evaluation of FAERS, and literature review. Cephalalgia 43:03331024221143538

    Google Scholar 

  155. Wee NK, Novak S, Ghosh D, Root SH, Dickerson IM, Kalajzic I (2023) Inhibition of CGRP signaling impairs fracture healing in mice. J Orthop Res 41:1228–1239

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Acknowledgements

This manuscript is a product of the 1st IHS/EHF Headache Research Academy promoted by the International Headache Society and the European Headache Federation.

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ALR, CG, ES, AD, DB, HN, LM, NC, and TG do not report a conflict of interest. EC has received honoraria from Novartis, Chiesi, Lundbeck, Medscape. PPR has received honoraria as a consultant and speaker, in the last three years, for: AbbVie, Amgen, Biohaven, Chiesi, Eli Lilly, Lundbeck, Medscape, Novartis, Pfizer and Teva. Her research group has received research grants from AbbVie, Novartis and Teva; and, has received funding for clinical trials from Alder, AbbVie, Amgen, Biohaven, Electrocore, Eli Lilly, Lundbeck, Novartis and Teva. She is the Honorary Secretary of the International Headache Society. She is in the editorial board of Revista de Neurologia, associate editor for Cephalalgia, Headache, Neurologia, Frontiers of Neurology. She is a member of the Clinical Trials Guidelines Committee and Scientific Committee of the International Headache Society. She has edited the Guidelines for the Diagnosis and Treatment of Headache of the Spanish Neurological Society. She is the founder of www.midolordecabeza.org. Pozo-Rosich P does not own stocks from any pharmaceutical company. RB is the John Hedley-Whyte Professor of Anesthesia and Neuroscience at the Beth Israel Deaconess Medical Center and Harvard Medical School. He has received research support from the NIH: R01 NS094198-01A1, R37 NS079678, R01NS095655, R01 NS104296, R21 NS106345, Allergan, Teva, Dr. Reddy, Eli Lilly, Trigemina and the Migraine Research Foundation. He is a reviewer for NINDS, holds stock options in AllayLampand Percept; serves as consultant, advisory board member, or has received honoraria from: Alder, Allergan, Amgen, Autonomic Technologies, Avanir, Biohaven, CGRP Diagnostic, Dr. Reddy’s Laboratory, ElectroCore, Eli Lilly, GlaxoSmithKline, Merck, Pernix, Theranica, Teva, and Trigemina. CME fees from Healthlogix, Medlogix, WebMD/Medscape, and Patents 9061025, 11732265.1, 10806890, US2021-0015908, WO21007165, US2021-0128724, WO21005497. JH received honoraria for consulting activities and/or serving on advisory boards and/or as a speaker from Allergan, Abbvie, Autonomic Technologies Inc., Cannovex BV, Chordate Medical AB, Eli Lilly, Hormosan Pharma, Lundbeck, MD-Horizonte, Novartis, Sanofi and Teva. He received personal fees for Medico-Legal work as well as from NEJM Journal Watch, Oxford University Press, Quintessence Publishing, Sage Publishing and Springer Healthcare. He holds stock options from Chordate Medical AB. He also reports a research grant from Bristol Myers Squibb. Jan Hoffmann serves as Associate Editor for Cephalalgia, Cephalalgia Reports, Journal of Headache and Facial Pain, Journal of Oral & Facial Pain and Headache as well as for Frontiers in Pain Research. He is an elected member of the Board of Trustees as well as the Science and Research Committee of the International Headache Society (IHS) and serves as a Council Member and Treasurer of the British Association for the Study of Headache (BASH). The article-processing charges for the article has been kindly sponsored by the European Headache Federation.

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Labastida-Ramírez, A., Caronna, E., Gollion, C. et al. Mode and site of action of therapies targeting CGRP signaling. J Headache Pain 24, 125 (2023). https://doi.org/10.1186/s10194-023-01644-8

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